How our ratings work, what they cover, how we set fees and how we manage conflicts of interest, as required under the EU ESG Ratings Regulation.
Calyx Global ratings and screenings are our own opinions of the quality of carbon credits, projects and carbon crediting programs, based on our published rating frameworks.
Last updated: 27 October 2026
GHG ratings explained
SDG ratings explained
ESR ratings explained
Program screenings explained
Estimated GHG ratings explained
Each rating product has a public explainer. For each topic below, the table gives a short answer and points to the part of the explainer with more detail.
Topic
GHG ratings (including estimated GHG ratings)
SDG ratings
ESR screenings
Carbon crediting program screenings
What the rating covers
What the rating tells you
GHG ratings (including estimated GHG ratings)
The rating expresses our confidence that each credit represents a unique, permanent tonne of CO2e reduced or removed. It assesses risks, not impacts. We assess four risk areas: additionality, over-crediting, permanence and overlapping claims. Estimated ratings provide an indication of the same; they are not a substitute for an expert rating.
SDG ratings
The rating assesses the quality of a project’s reported contributions to the UN Sustainable Development Goals. It assesses impacts, not risks. We assess impacts mapped to the 17 SDGs and their targets.
ESR screenings
The screening identifies a project’s potential environmental and social risks and how well they are managed. It identifies risks in ten areas (biodiversity, resource efficiency, stakeholder engagement and grievance mechanisms, benefit sharing, community health and safety, cultural heritage, gender equity, human rights and indigenous peoples, labour rights and land rights).
Carbon crediting program screenings
The screening assesses our confidence that each carbon crediting program has the minimum governance, transparency and operational features needed to issue credits.
Scope and topics
GHG ratings (including estimated GHG ratings)
The scope of the rating is E, environmental: whether each credit delivers the greenhouse gas reduction or removal it claims. Because the scope is limited to environmental factors, there is no weighting across environmental, social and governance factors.
Our risk areas are not mapped to the European Sustainability Reporting Standards (ESRS). The closest ESRS topic is E1 Climate change, which includes disclosure of carbon credits.
SDG ratings
The scope of the rating is E and S: whether there is evidence of a project’s beneficial impact, mapped to the 17 SDGs and their targets. Each contribution is scored on the level of change the project shows and the quality of evidence provided. The score for each SDG target is added together, with equal weighting, into an overall rating. SDG ratings are mapped to the UN SDGs, not to ESRS topics.
ESR screenings
The scope of the screening is E, S and G. Each area receives its own risk level; we do not combine them into an overall score, so there is no weighting. ESR areas are based on IFC, World Bank and UNDP standards, among others, not on ESRS topics.
Read more in ESR screenings explained — Environmental and social safeguards areas
Carbon crediting program screenings
The scope of the screening is G: how the program is operated, assessed against 31 criteria that cover governance, rules and procedures, stakeholder engagement, transparency, validation and verification and registry operations. Program screenings are not mapped to ESRS topics.
Read more in Program screenings explained — Areas of assessment
Rating scale
GHG ratings (including estimated GHG ratings)
Ratings are absolute, on a scale from AAA (lowest risk) to D (highest risk). Estimated ratings show a range on the same scale.
SDG ratings
Ratings are absolute, on a scale from +1 to +5, reflecting the quality and impact of a project’s SDG contributions; +5 is the highest.
ESR screenings
Screenings are absolute on a scale from low to moderate, high or critical.
Carbon crediting program screenings
Screenings are absolute on a scale from fail to bronze, silver or gold, based on the strength of their operational features and whether they show best practice. A program fails if it does not meet six minimum criteria.
Paris Agreement and other international agreements
GHG ratings (including estimated GHG ratings)
GHG ratings are aligned with, and contribute to, the objectives of the UN Framework Convention on Climate Change and the Paris Agreement. They focus on identifying “what the atmosphere sees” and do not conflate other elements into the assessment. Our approaches to emissions estimation are based on the Intergovernmental Panel on Climate Change (IPCC) GHG inventory methods. Furthermore, we take into account the Article 6.4 activity standard for projects and decisions made by the Article 6 Supervisory Body. Our GHG ratings are also aligned with the International Civil Aviation Organization (ICAO) Carbon Offsetting and Reduction Scheme for International Aviation’s (CORSIA) Emissions Unit Criteria, in particular the Carbon Offset Credit Integrity Assessment Criteria. However, our ratings go one step further by making assessments at the project, rather than methodology, level.
SDG ratings
SDG impact ratings contribute to the objectives of the Paris Agreement including Article 2, “to strengthen the global response to the threat of climate change, in the context of sustainable development and efforts to eradicate poverty” as well as its Crediting Mechanism (Article 6, PACM), which have objectives to promote and foster sustainable development. Calyx Global has, from the very start, included SDG ratings to contribute to these goals. Calyx Global’s framework systematically builds on UN SDG targets and indicators to measure, track, and validate sustainable development outcomes of carbon projects. In doing so, it takes into account the targets and objectives of the Paris Agreement by formally adopting the United Nations definition of Sustainable Development, as per the UN 2030 Agenda for Sustainable Development.
ESR screenings
Paris Agreement decisions require ‘cooperative approaches’ (including the PACM) to include safeguards. REDD decisions under the Paris Agreement also refer to safeguards. Our ESR screenings are aligned with these concepts and contribute to the goal of promoting mitigation that does not harm people or the environment. Our safeguard assessments are based on international standards, including the IFC Performance Standards, the World Bank Environmental and Social Framework and the UN Development Programme’s Social and Environmental Standards. Our ESR screenings also are based on the following international agreements:
Carbon crediting program screenings
Our Program screenings are aligned with the International Civil Aviation Organization (ICAO) Carbon Offsetting and Reduction Scheme for International Aviation’s (CORSIA) Emissions Unit Criteria (at the program level), but add some additional elements.
How the rating is produced
Rating framework overview
GHG ratings (including estimated GHG ratings)
The GHG rating frameworks are titled “Calyx Global greenhouse gas integrity framework (GIF)”, “Project assessment framework(s) (PAF)” and “Estimated project assessment framework(s) (ePAF)”. GHG rating frameworks apply to credits from project types in the carbon market. Each project’s credits are rated using a PAF built for its project type. Published ratings look back at credits already verified. Preliminary ratings look forward at not yet verified credits. Estimated ratings may be backward or forward looking. They apply the same frameworks through a rule-based estimation methodology, using information that SmartScan, our proprietary estimation tool, extracts and classifies with AI. We review our expert rating frameworks at least once a year with our independent GHG expert panel. The estimation methodology is maintained by our R&A team, with each version approved by an R&A Director.
Read more in GHG ratings explained and GHG estimated ratings explained
Last update date and change history: GHG ratings explained — Appendix: version and change log; GHG estimated ratings explained — Appendix: version and change log
SDG ratings
The SDG rating frameworks are titled “Calyx Global SDG impact framework” and “Project type SDG ID”. SDG rating frameworks apply to projects active in the carbon market. Ratings look back at projects already certified for their SDG contributions (for example, under CCB, SD VISta or Gold Standard for the Global Goals) whose claims a third-party auditor has verified. Preliminary ratings look forward at projects not yet verified. We review our frameworks at least once a year with our independent SDG expert panel.
Read more in SDG ratings explained
Last update date and change history: SDG ratings explained — Appendix: version and change log
ESR screenings
The ESR screening frameworks are titled “Calyx Global ESR screening framework” and “Project type ESR ID”. Screenings look back at projects already verified. Preliminary screenings look forward at projects not yet verified. We review our frameworks at least once a year with our independent safeguards expert panel.
Read more in ESR screenings explained
Last update date and change history: ESR screenings explained — Appendix: version and change log
Carbon crediting program screenings
The program screening framework is titled “Carbon crediting program screening framework”. This framework applies to carbon crediting programs active in the carbon market. Screenings look back at programs already operating. We review the screening framework at least once a year with our independent GHG expert panel.
Read more in Program screenings explained
Last update date and change history: Program screenings explained — Appendix: version and change log
Models and key assumptions
GHG ratings (including estimated GHG ratings)
Ratings combine risk levels for each area using a demerit-based scoring model. Additionality caps the overall rating. Estimated ratings apply the same scoring model as above, based on information extracted by SmartScan; they may show a rating range.
Read more in GHG ratings explained — Scoring system; Appendix: key assumptions
Read more in GHG estimated ratings explained — Estimated ratings approach; Appendix: key assumptions
SDG ratings
Each contribution is scored along a results chain of output, outcome and impact (theory of change); an impact only scores if an outcome and output come before it.
Read more in SDG ratings explained — Scoring system; Appendix: models and assumptions
ESR screenings
Each safeguard area receives a risk level based on the potential impact and likelihood of identified risks and the management measures in place. Areas are not combined.
Read more in ESR screenings explained — Risk categorization and reporting
Carbon crediting program screenings
Programs must meet six minimum criteria to pass. The remaining 25 best-practice criteria are assessed and together scored to give Bronze, Silver or Gold.
Read more in Program screenings explained — Minimum criteria to pass
How projects are categorized
GHG ratings (including estimated GHG ratings)
Projects are categorized by project type, using Calyx Global’s own taxonomy.
SDG ratings
Projects are categorized using the same taxonomy as for GHG ratings.
ESR screenings
Projects are categorized using the same taxonomy as for GHG ratings.
Carbon crediting program screenings
n/a
Data sources and updates
GHG ratings (including estimated GHG ratings)
Expert ratings use public information: registry documents, research, media coverage, satellite data and local regulation. Preliminary ratings may also use draft project documents from the client who commissioned the rating. We rate new credits as they are verified and revisit ratings when material new information emerges. Every rating is approved by a Calyx Global Director.
Estimated ratings use registry documents, other public sources and Calyx Global benchmark datasets, or documents a customer uploads, which stay private to them. We notify developers when we publish an estimated rating. Each estimation methodology version is approved by an R&A Director.
We do not rely on CSRD sustainability statements or SFDR disclosures, though analysts may refer to them occasionally.
Read more in GHG ratings explained — PAFs
Read more in GHG estimated ratings explained — Estimated ratings approach
SDG ratings
Ratings draw on project documents published on carbon registries. We rate certified projects and revisit a published rating when material new information emerges. Preliminary ratings can also use draft versions of certification documents. We revisit preliminary ratings when the project is certified. Every rating is reviewed and approved by a Calyx Global Director. Our frameworks do not rely on sustainability statements prepared under Directive 2013/34/EU (CSRD) or disclosures made under Regulation (EU) 2019/2088 (SFDR). Analysts may occasionally refer to such information where it is relevant to a specific rating.
ESR screenings
Screenings draw on project documents published on carbon registries, other public information such as academic papers, reports and media coverage, and research on local practices and regulation. We interview the project developer as part of each screening; an in-depth option adds interviews with other stakeholders. Information from developer interviews may not be public. We screen verified projects and revisit a published screening when material information emerges. Preliminary screenings can also use draft versions of project documents. We revisit preliminary ratings when a project is verified. Every screening is reviewed and approved by a Calyx Global Director. Our frameworks do not rely on sustainability statements prepared under Directive 2013/34/EU (CSRD) or disclosures made under Regulation (EU) 2019/2088 (SFDR). Analysts may occasionally refer to such information where it is relevant to a specific rating.
Read more in ESR screenings explained — Project developer communication in the ESR screening process
Carbon crediting program screenings
Screenings use information published on the program’s website and other public sources. We invite programs to review our findings. We screen new programs and program versions as they are published and revisit a screening when material new information emerges. Every screening is reviewed and approved by a Calyx Global Director. Our frameworks do not rely on sustainability statements prepared under Directive 2013/34/EU (CSRD) or disclosures made under Regulation (EU) 2019/2088 (SFDR). Analysts may occasionally refer to such information where it is relevant to a specific rating.
Scientific evidence
GHG ratings (including estimated GHG ratings)
Our frameworks draw on published research and are reviewed and approved by an independent panel of GHG experts. Estimated ratings use benchmarks drawn from the same independent sources. The estimation methodology is maintained by our R&A team and is not reviewed by the panel.
SDG ratings
Our frameworks are built upon the UN SDGs at the target and indicator level and are reviewed and approved by an independent panel of SDG experts.
Read more in SDG ratings explained — Criteria for rating SDG contributions
ESR screenings
Our frameworks are built upon standards including the IFC, the World Bank, the UNDP, Fair Trade Climate and others, and are reviewed and approved by an independent panel of safeguard experts.
Carbon crediting program screenings
Our frameworks draw on CORSIA’s Emissions Unit Criteria and other published research and are developed, reviewed and approved by an independent panel of GHG experts.
Use of artificial intelligence
GHG ratings (including estimated GHG ratings)
The use of AI is not a routine part of applying our GHG rating frameworks. For estimated ratings, SmartScan, our proprietary estimation tool, uses AI to extract and classify information from project documents and, in some cases, other public sources; the rating is then determined by a rule-based estimation methodology. AI can produce errors, so estimated ratings are indicative.
Read more in GHG estimated ratings explained — Estimated ratings approach
SDG ratings
The use of AI is not a routine part of applying our SDG rating frameworks.
ESR screenings
The use of AI is not a routine part of applying our ESR screening frameworks.
Carbon crediting program screenings
The use of AI is not a routine part of applying our program screening frameworks.
Limitations
Limitations of our data, methodology and information
GHG ratings (including estimated GHG ratings)
An important limitation is the accuracy and completeness of project documents published on carbon registries and the variability in what each registry requires (for example, some registries do not require a .kml file which provides important geographic data and coordinates for the project, while others do not require any financial documentation). For expert ratings, when project documents are incomplete, we conduct additional research to address gaps to the extent possible. Ratings reflect the information available on the rating date. Our ratings also rely on assumptions and reference values, such as information in academic literature or government data sets. Where these differ from a project’s actual conditions, the rating may overstate or understate risk. Estimated ratings draw on fewer elements than expert ratings, focusing on the key factors that are most critical for integrity. Where information is missing, we widen the rating range or apply a conservative assumption, and flag the gap.
Read more in GHG ratings explained — Appendix: key assumptions
Read more in GHG estimated ratings explained — Appendix: key assumptions
SDG ratings
An important limitation is the accuracy and completeness of project documents published on carbon registries, as well as variability across the different SDG certification programs. Ratings rely on key assumptions: we apply the most recent verified information to generate a rating that applies to all vintages, assuming contributions build up over time, and we score contributions regardless of how many carbon credits are claimed. Ratings reflect the information available on the rating date.
Read more in SDG ratings explained — Appendix: models and assumptions
ESR screenings
An important limitation is the accuracy and completeness of project documents published on carbon registries and the variability in what each registry requires. When project documents are incomplete, we conduct additional research to address gaps to the extent possible. Screenings do not involve site visits. Screenings reflect the information available on the screening date.
Read more in ESR screenings explained — Appendix: key assumptions
Carbon crediting program screenings
An important limitation is the accuracy and completeness of documents that each program publishes on its operations. We invite programs to review our findings and point us to additional public information. We assess the program’s published rules and procedures, not how consistently they are applied in practice. Screenings reflect the information available on the screening date.
Calyx Global, Inc.
Delaware, USA · Issues our ratings
Calyx Global Private Limited
Singapore · 100% owned · No rating activities
Calyx Global Ratings Ireland Limited
Ireland · 100% owned · EU legal representative
Calyx Global, Inc.
Delaware, USA
Issues our ratings
Calyx Global Private Limited
Singapore · 100% owned
No rating activities
Calyx Global Ratings Ireland Limited
Ireland · 100% owned
EU legal representative
None of these companies provides consulting, credit ratings, benchmarks, investment, audit, banking or insurance services.
Fees for Calyx Global's ratings of carbon credits, projects and carbon crediting programs are set by reference to a standard rate structure applied consistently across similar clients. Adjustments may apply where a defined discount category is met. Fees are not linked to or adjusted for the outcome of any rating, and no one who produces, reviews or approves a rating takes part in negotiating fees with a rated party. These controls are how Calyx Global ensures its fees are fair, reasonable, transparent, and non-discriminatory.
The elements considered when setting a fee are the customer type, the scale of the customer's activity, the specific product and configuration purchased, the scope of work for engagement, the duration of the subscription or engagement, and whether the product is purchased as part of a defined bundle. Ratings are available on a standalone basis, and purchasing other Calyx Global services is not a condition of obtaining a rating.
At this time, Calyx Global primarily operates a subscription-paid model, where users pay for access to Calyx Global ratings. Calyx Global is also piloting an issuer-paid model, under which project developers pay for ratings of their own projects. In all cases, fees are set using the criteria described above and do not depend on the rating outcome. Payment is either a periodic subscription fee, a one-off engagement fee, or a licence fee. In 2025, 87% of Calyx Global's total annual revenue was derived from subscriptions and/or ratings, 0% from an issuer-paid model, and 13% from non-rating services.
We believe carbon credit ratings should be guided by science, not financial interest. For the market to grow, it must be built on a bedrock of trust and confidence. That means there should be no question about our incentives as we evaluate projects—which is why we have established strict rules and governance to prevent conflicts of interest.
See the main conflict of interest risks and how we manage them.Questions or concerns about a rating? See our feedback and complaints process.
